Hi can anyone tell me what would be the most common fault on why an airbag light would come on the dash board ?

I had recently taken the steering wheel off but if there was a fault there it wouldn't have taken 3 weeks to show

Someone told me it could be something to do with under the drivers seat. ?

I have the suberb elegance 1.9 tdi

I have also plugged in a can obd 2 reader and it doesn't detect any faults any help would be great thanks

Check/toggle passenger airbag switch in the glove box, (only if you have it).

But if you disconnected/reconnected steering wheel airbag, perhaps connection is loose there?

Then you just have ****ty obd reader. Take VAG-COM from Ross and you should see the fault code. Did you take the battery off, when you took the steering wheel off? If not, then there's fault code stored in memory, that airbag has been detached. You need to clear it with VAG-COM. Worst is if you managed to break or do something to steering angle sensor. Then the light will come on with all the other ones (ASR, brakes etc).

I suspect a fault code that needs to be cleared and if that doesn't work, then take airbag off again and check wiring (with love of god - battery out).

It could be very helpful to know the fault code so go and check somebody who has VAG-COM. Quite a lot have them in the message board, so just look around near your home and ask them.

About the wiring under the seat - it's good to take airbag plug off under the seats and clean them. There could be condensed water, that's giving the fault code.